Hyperthermia in the treatment of cancer.

The expectation that hyperthermia would be effective in the treatment of cancer is attributable to a theoretical viewpoint based upon biological studies. Cancer cells, which characteristically are hypoxic with poor nutrition and low pH, are sensitive to temperatures over 42.5 degrees C. This is the theoretical basis which assures the effectiveness of hyperthermia when used in combination with radiation therapy. Previous clinical studies have shown that a combination hyperthermia and radiation therapy is an effective treatment for superficial tumors, thus expanding the range of cancer therapy. When used for deeply seated cancer, this combination enhances the efficiency of therapy. It is, however, necessary to improve the heating techniques and methods of thermometry. Fundamental studies are now being actively pursued in respect of combined hyperthermia and chemotherapy. However, inadequacy of clinical material hinders evaluation. The combination of whole-body hyperthermia with anti-cancer agents presents so far, unsolved problems, such as determination of applicable anatomical regions and prevention of complications.